Dyeing process



be a definite change in color.

UNITED STATE s PATENT orries DYEING PROCESS Robert ant-a Jackson Heights, a. 2., m... to of America, a corporation Celanese Corporation of Delaware No Drawing.

v 1 is claims. (Cl. 8-61) This invention relates to the treatment of ma-- Other objects of my invention will ap ear from the following detailed description. v In the coloration of textile materials it is very desirable that the colors produced on the ma- Applies Serial No. 450 825 terials be as fast as possible to light, washing andto other agencies such as acid fumes. Many dyestuffs yield on organic derivative of cellulose materials desirable shades which are 'fast to .washing but these dyestuffs often suffer from a lack of fastness to acid fumes. when fabrics to which these dyestuffs have been applied are exposed to acid fumes, for example, the products of combustion of coal, gas, etc., the color undergoes achangein shade. This change is usually referred to as acid fading. "The change which occurs may be a dulling of the'brightness 0f the shade in some instances,land in others there may This undesirable effect is frequently observed in the case of many anthraquinone dyestuffs which yield valuable blue colors on organic derivative of cellulose materials. when fabrics dyed with these colors are exposed to acid fumesthe colors change. fromv a pure blue shade to one having a reddish cast.

On continued exposure to the acid fumes'the blue color may even change to a, pink color.

ing the resistance or these dyes to acid fading are of great commercial importance. V

. I have now discovered that the acid fading characteristicsof organic derivativeof cellulose textile materials dyed with water-insoluble anthraquinone dyestuffs of the dispersol type'may be substantially improved. These desirable, results may be achieved if such dyed textile materials are treated with tannic acid so that the tannic acid is precipitated and retained within the structure of the material in the form ofan insolubletannate. When dyed textile materials are. treated in this way. the dyed material obtained exhibits excellent resistance toacid fading and .the textile material for substantial periods with little or no effect tion September 20, 1942.

may be exposed to acid fumes up n the color of the material.

I'h insoluble tannate may natingthe material with a solution of tannic acid, then treating the impregnated material with asolution or suspension of a metal compound which reacts with the tannic acid to form an insoluble tannate. Conversely, the dyed textile material may first be treated with a solution or suspension of a metal compound which is capable of reacting with tannlc acid to form an insoluble tannate, and the treated textile'material may then be padded or otherwise impregnatedwith a solution of tannic acid to form the insoluble tannate. Compounds of metals such as, for example, calcium, magnesium, ironand manganese lulose textile materials, it is preferable that the textile material be driedafter being impreg-.

nated with either the tannieacid or the metal compound prior to the formation and precipitation of the tannate. I'hus, when treating fabrics the latter may be padded with a solution or suspension of the metal compound or of tannic acid, which may be maintained at a-temperature of from 20'to 100 C. After being padded, the fabric may be-dried by passing through a drying chamber through which air heated to 85. to about 120? o. is circulated. After-the fabric'is dried,

Such. changes naturally restrict the range of useful ness of these dyestuffs and methods of increas-' theinsoluble tannate is formed in the treated textile material by padding-it with a solution of tannic acid'if the initial treatment was with a metal compound, or by padding with a solution or suspenson of a metal compound if the initial padding waswith a solution of ftannic acid.

- The solution employed for treating the dyed o'rgani'c derivative-"0f cellulose textile materials may be of varying concentrations. In the case of tannic acid the solution may be of a concentrationof from 0.1 to 10% by weight, optimum re- 1 suits, however, being achieved with solutions of concentrations of about0.5% by weight. The solutions or suspensions of the metal compound which are employed may contain from about 0.5

to 20 or more by weight of the metal compound depending upon the concentration of the tannic acidsolution with which it is to be reacted. Thus, for example, when calcium hydroxide is employed as the compound to forminsolu be precipitatedwithln the dyed textile materialsin several ways. .This may be done, for example, by first impreg-- all may be employed to form waterinsoluble tannates. 1 In treating the dyed organic derivative of celting or dispersing agents may 'be sulfonated oils,

sulfated long chain fatty alcohols, sulfonated fatty acid esters, alkyl substituted aryl sulfonates; and the like.

mixed esters such as cellulose acetate-propionate and cellulose acetate-butyrate, while examples of cellulose ethers are ethyl cellulose and benzyl cellulose. Not only may dyed fabrics be treated to improve their resistance to acid fading, but the acid fading characteristics of dyed textile materials in other forms, such as, for example, yarns andfilaments in'- the form of hanks or wound on bobbins, orstaple fiber in the form of a top may likewise be improved by my novel treatment.

The amount of insoluble tannate precipitated in the dyed organic derivative of cellulose tex-.-

tile material in accordance with my invention may be from about 0.1 to 10% on the weight of the fabric or other textile materiaL In order further to illustrate my invention but.

without being limited thereto, the following examples are given,

sample I A cellulose acetate with 1% of 1:4 di-methylamino-anthraquinone is padded with a 0.5% solution of tannic acid at 40 C. and dried. The dried fabric is then paddedwith a suspension containing 1%. by

weight of calcium hydroxide. The reaction be tween the calcium hydroxide and the tannic acid causes'an insoluble precipitate of calcium tannate to form in the fabric. The fabric is washed for 10 minutes at 70 C. and then exposed to an atmosphere containing acid fumes. After 40 hours exposure the color of the treated fabric is altered only slightly, the change being only that the color now has a slight reddish cast. Un- I treated dyed fabric exposed for 40 hours to the same acid conditions undergoes a complete change of color, the blue fading to a pink color. v Example]! i A cellulose acetate fabric I is padded with a 1% solution of calcium hydroxide at 40" C. and dried.-, The dried fabric is then padded with a 0.5% solution. oftannic acid which reacts with the calcium hydroxide to form insoluble calcium tannate in the fabric. Aftentreatment the fabric is washed for 10 minutes at 70 C. The treated fabric is then exposed to an acid atmosphere. for 40 hours with only a slight change in shade, i. e. a slight reddish cast on the blue color, while untreated dyed fabric changes completely from the original blue shade pink under like conditions of exposure.

Example HI fabric dyed in a blue suede dyed as in Example It is to bejunderstood' that theforegoing detaileddescriptionis merely given by way of illustration and that many variations may be made therein without departing from the spirit'of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

' 1. Process for improving the fastness to acid fumes of colorations on organicderivative of cellulose textile materials dyed with water-insoluble anthraquinone dyes of the. dispersoltype.

which comprises forming a water-insoluble tannic acidsalt of a "metal on said colored organic derivative of cellulose textile material.

2.'Process for improving the fastness to acid" fumes of colorations 'on cellulose acetate textile materials dyed with water-insoluble anthraquinone dyes of the dispersol type, which comprises forming a water-insoluble tannic acid salt of a metal on said colored cellulose acetate textile material. 1 r 3. Process for improving the fastness to acid fumes of colorations on cellulose acetate textile materials dyed with water-insoluble anthraquinone dyes of the dispersal type which comprises forming calcium tannate on said colored cellulose acetate textile material.

4. Process for improving the fastness of colorations on organic derivative of-cellulose textile marial with a solution of a metal compound adapted A cellulose acetate fabric dyed as in Example I is padded with a 1% solution of calcium hydroxide at 40? C. and dried. The dried fabric isthen padded with a 0.5% solution of tannic acid containing 2% by weight of Parapon R," an agent comprising a highly suifonated fatty acid ester and a softener. which softener is likewise a sulfonated fatty acid ester. After treatment, the fabric is washed. The treated dyed fabric is strongly resistant to acid fading and shows little change after a 40 hour exposure to acid fumes. I

'While my invention has been more pa 'rticularly described in connection with the'treatment of cellulose acetate textile materials, other organic derivative of cellulose textile materials, such as cellulose esters and cellulose others, may likewise be treated in accordance with the process of my invention. Examples of cellulose esters are cel-,

lulose propionate and cellulose butyrate, and

to react with said tannic acid and form a waterinsoluble metal tannate thereon.

5. Process for improving the fastness of colorations on organic derivative of cellulose textile materials dyed with water-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises impregnating saiddyed textile material .with'a solution of a metal compound which forms a water-insoluble ,tannic acid salt on reaction with tannic acid, drying the impregnated material, and treating the dried material with'a z,

solution of tannic acid. '65.

ti0ns on cellulose acetate'textile materials dyed 6; Process for improving the fastness of colorawith water-insoluble anthraquinone dyes of the dispersal type to acid fumes, which comprise impregnating said dyed textile material with a solution of tannic acid,- drying the impregnated material, and treating said dried material with a so.- lutionof a metal compound adapted to react with tannate thereon.

" 7. Proces for improvins the fastness of colorasaid tannic acid and form a water-insoluble metal ing the dried material with a solution of tannic acid.

8. Process for improving the fastness of colora- 1o tions on a cellulose acetate fabric dyed with waa ter-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises padding said fabric with a solution of tannic acid, drying the 1 treated fabric, and padding said dried fabric with a suspension of calcium hydroxide to form a water-insoluble calcium tannate on said dyed fabric.

9. Process for improving the fastness of colorations on a cellulose acetate fabric dyed with water-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises padding said dyed fabric with a suspension of calcium hydroxide, drying the treated fabric, and padding said dried fabric with a solution of tannic acid to form a water-insoluble tannate on said dyed fabric.

10. Process for improving the fastness of col- Patent No.- 2,571,221.

Bonner amms orations on a cellulose acetate fabric dyed with water-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises padding said dyed fabric with asuspension of 'calcium hydroxide, drying the treated fabric, and 7 padding said ,dried fabric with a. solution of tannic acid containing a wetting and softening agent to form a water-insoluble calcium tannate on said dyed fabric.

11. Organic derivative of cellulose textile materials dyed with water-insoluble anthraquinone. dyes of the dispersol type having improvedfastness to acid fumes and having incorporated therein a water-insoluble tannate of a metal.

l2. Cellulose acetate textile materials dyed with water-insoluble anthraquinone dyes of the dispersol type having improved fastriess to acid fumes and having incorporated therein a. waterinsoluble tannate of a metal.

13. Cellulose acetate textile material dyed'with a water-insolubleanthraquinone dyestufi of the dispersol type having improved fastness to acid fumes and having calcium tannate incorporated therein.

ROBERT BURNS.

csarrirca'rs or conaacrror.

March 15, 19i

, It is hereby certified 'that error appears in the printed specification of the above numbered patent requiring correction as follows s Page 5 first" column line 2 5 claim 9, before the word '"tannate insert arid that the said letters' Patent 'shou'1d be read'with this correction there in that the some conform to the record of the casein the Patent Office.

Signed and'sea1ed th1s Eth'day' of June, A. D. 1911.5. I 3

(Seal) Q Leslie Frazer Acting Commissioner of Patents,

ing the dried material with a solution of tannic acid.

8. Process for improving the fastness of colora- 1o tions on a cellulose acetate fabric dyed with waa ter-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises padding said fabric with a solution of tannic acid, drying the 1 treated fabric, and padding said dried fabric with a suspension of calcium hydroxide to form a water-insoluble calcium tannate on said dyed fabric.

9. Process for improving the fastness of colorations on a cellulose acetate fabric dyed with water-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises padding said dyed fabric with a suspension of calcium hydroxide, drying the treated fabric, and padding said dried fabric with a solution of tannic acid to form a water-insoluble tannate on said dyed fabric.

10. Process for improving the fastness of col- Patent No.- 2,571,221.

Bonner amms orations on a cellulose acetate fabric dyed with water-insoluble anthraquinone dyes of the dispersol type to acid fumes, which comprises padding said dyed fabric with asuspension of 'calcium hydroxide, drying the treated fabric, and 7 padding said ,dried fabric with a. solution of tannic acid containing a wetting and softening agent to form a water-insoluble calcium tannate on said dyed fabric.

11. Organic derivative of cellulose textile materials dyed with water-insoluble anthraquinone. dyes of the dispersol type having improvedfastness to acid fumes and having incorporated therein a water-insoluble tannate of a metal.

l2. Cellulose acetate textile materials dyed with water-insoluble anthraquinone dyes of the dispersol type having improved fastriess to acid fumes and having incorporated therein a. waterinsoluble tannate of a metal.

13. Cellulose acetate textile material dyed'with a water-insolubleanthraquinone dyestufi of the dispersol type having improved fastness to acid fumes and having calcium tannate incorporated therein.

ROBERT BURNS.

csarrirca'rs or conaacrror.

March 15, 19i

, It is hereby certified 'that error appears in the printed specification of the above numbered patent requiring correction as follows s Page 5 first" column line 2 5 claim 9, before the word '"tannate insert arid that the said letters' Patent 'shou'1d be read'with this correction there in that the some conform to the record of the casein the Patent Office.

Signed and'sea1ed th1s Eth'day' of June, A. D. 1911.5. I 3

(Seal) Q Leslie Frazer Acting Commissioner of Patents, 

